Summary of Work: There are only a few large studies of high environmental pollution and pregnancy. We have collected data on over 3,000 pregnant women in two urban areas of Ukraine, a former Soviet republic, where pollution is reputedly high; we took placentas and breast milk from 2,200 of them during delivery and hospitalization. We have been analyzing these data for the last two years. We have just published our findings on the levels of organochlorines and dioxin compounds in human milk. We have also completed the final draft of a paper on polycyclic aromatic hydrocarbons in placenta, and have begun the study of four metals in placenta. In general, the toxicants appear at low levels in this sample in spite of reports of high pollution. A paper on the difficulty of measuring pollution in the former eastern bloc and how we did it is planned. In parallel, we have described the reproductive outcome of the population from which the women we study were drawn. We have finished a paper on the rate of preterm birth in our sample in the two urban areas, and will continue with an examination of the rate of low birth weight. We will also describe hospitalization procedures during pregnancy in urban Ukraine, which may explain some of the notable findings in the population such as the high rate of fetal loss and the low rate of preterm birth and low birth weight. - Eastern Europe, eastern bloc, reproduction, pregnancy, pollution - Human Subjects